Revert "Add Iterable bitset class."

src/common/BitSetIterator.h

-//
-// Copyright 2015 The ANGLE Project Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-//
-// BitSetIterator:
-//   A helper class to quickly bitscan bitsets for set bits.
-//
-
-#ifndef COMMON_BITSETITERATOR_H_
-#define COMMON_BITSETITERATOR_H_
-
-#include <stdint.h>
-
-#include <bitset>
-
-#include "common/angleutils.h"
-#include "common/platform.h"
-
-namespace angle
-{
-template <size_t N>
-class BitSetIterator final
-{
-  public:
-    BitSetIterator(const std::bitset<N> &bitset);
-    BitSetIterator(const BitSetIterator &other);
-
-    class Iterator final
-    {
-      public:
-        Iterator(const std::bitset<N> *bits);
-        Iterator &operator++();
-
-        bool operator!=(const Iterator &other) const { return mBits != other.mBits; }
-        size_t operator*() const { return mCurrentBit; }
-        size_t getNextBit() const;
-
-      private:
-        unsigned long long mBits;
-        size_t mCurrentBit;
-    };
-
-    Iterator begin() const { return Iterator(&mBits); }
-    Iterator end() const { return Iterator(nullptr); }
-
-  private:
-    const std::bitset<N> &mBits;
-};
-
-template <size_t N>
-BitSetIterator<N>::BitSetIterator(const std::bitset<N> &bitset)
-    : mBits(bitset)
-{
-    static_assert(N <= 64, "IterableBitSet only supports up to 64 bits.");
-}
-
-template <size_t N>
-BitSetIterator<N>::BitSetIterator(const BitSetIterator &other)
-    : mBits(other.mBits)
-{
-}
-
-template <size_t N>
-BitSetIterator<N>::Iterator::Iterator(const std::bitset<N> *bits)
-    : mBits(bits ? bits->to_ullong() : 0ull), mCurrentBit(bits ? getNextBit() : 0ull)
-{
-}
-
-template <size_t N>
-typename BitSetIterator<N>::Iterator &BitSetIterator<N>::Iterator::operator++()
-{
-    mBits &= ~(1ull << mCurrentBit);
-    mCurrentBit = getNextBit();
-    return *this;
-}
-
-template <size_t N>
-size_t BitSetIterator<N>::Iterator::getNextBit() const
-{
-#if defined(_WIN64)
-    static_assert(sizeof(uint64_t) == sizeof(unsigned long long), "Incompatible sizes");
-
-    unsigned long firstBitIndex = 0ul;
-    unsigned char ret           = _BitScanForward64(&firstBitIndex, mBits);
-
-    if (ret != 0)
-        return static_cast<size_t>(firstBitIndex);
-#elif defined(_WIN32)
-    static_assert(sizeof(size_t) == sizeof(unsigned long), "Incompatible sizes");
-
-    unsigned long firstBitIndex     = 0ul;
-    const unsigned long BitsPerWord = 32ul;
-
-    for (unsigned long offset = 0; offset <= BitsPerWord; offset += BitsPerWord)
-    {
-        unsigned long wordBits = mBits >> offset;
-        unsigned char ret      = _BitScanForward(&firstBitIndex, wordBits);
-
-        if (ret != 0)
-        {
-            return static_cast<size_t>(firstBitIndex + offset);
-        }
-    }
-#elif defined(ANGLE_PLATFORM_LINUX) || defined(ANGLE_PLATFORM_APPLE)
-    if (mBits != 0)
-    {
-        return __builtin_ctzll(mBits);
-    }
-#else
-#error Please implement bit-scan-forward for your platform!
-#endif
-    return 0;
-}
-
-// Helper to avoid needing to specify the template parameter size
-template <size_t N>
-BitSetIterator<N> IterateBitSet(const std::bitset<N> &bitset)
-{
-    return BitSetIterator<N>(bitset);
-}
-
-}  // angle
-
-#endif // COMMON_BITSETITERATOR_H_

src/common/BitSetIterator_unittest.cpp

-//
-// Copyright 2015 The ANGLE Project Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-//
-// BitSetIteratorTest:
-//   Test the IterableBitSet class.
-//
-
-#include <gtest/gtest.h>
-
-#include "common/BitSetIterator.h"
-
-using namespace angle;
-
-namespace
-{
-class BitSetIteratorTest : public testing::Test
-{
-  protected:
-    std::bitset<40> mStateBits;
-};
-
-TEST_F(BitSetIteratorTest, Iterator)
-{
-    std::set<size_t> originalValues;
-    originalValues.insert(2);
-    originalValues.insert(6);
-    originalValues.insert(8);
-    originalValues.insert(35);
-
-    for (size_t value : originalValues)
-    {
-        mStateBits.set(value);
-    }
-
-    std::set<size_t> readValues;
-    for (size_t bit : IterateBitSet(mStateBits))
-    {
-        EXPECT_EQ(1u, originalValues.count(bit));
-        EXPECT_EQ(0u, readValues.count(bit));
-        readValues.insert(bit);
-    }
-
-    EXPECT_EQ(originalValues.size(), readValues.size());
-}
-
-}  // anonymous namespace

src/libGLESv2.gypi

@@ -8,7 +8,6 @@
         # These file lists are shared with the GN build.
         'libangle_common_sources':
         [
-            'common/BitSetIterator.h',
             'common/Float16ToFloat32.cpp',
             'common/MemoryBuffer.cpp',
             'common/MemoryBuffer.h',

src/tests/angle_unittests.gypi

@@ -15,7 +15,6 @@
         # This file list will be shared with the GN build.
         'angle_unittests_sources':
         [
-            '<(angle_path)/src/common/BitSetIterator_unittest.cpp',
             '<(angle_path)/src/common/Optional_unittest.cpp',
             '<(angle_path)/src/common/mathutil_unittest.cpp',
             '<(angle_path)/src/common/matrix_utils_unittest.cpp',